Fluid passage for drilling tools



0 R Y ww Z mh E l l l N j I|H\ 1 I ,Jnvi N/ R 2 d w d il" f, N r. 1M A HM W 7 Feb. 22, 193.8. J. A. zUBLlN FLUID PASSAGE FOR DRILLING TOOLSFiled June 2, 1936 Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE 4claims.

v'Ihe present invention relates generally to tools for drilling wells,and is particularly concerned with means for conducting' and directingto the bottom of the hole the circulation fluid used to 5` clean thecutting elements and carry cuttings to the surface.

In drilling tools of various types, the circulation fluid is oftendischarged from the tool at a point considerably above the bottom of thehole. As a result, the cutting elements are sometimes not cleaned aseffectively as they should be, and the stream of uid does not clear awayall the cuttings, but instead leaves a layer of them over the bottom. Tooperate with best eiliciency, the stream of fluid should be led as nearto the bottom of the hole as possible and in such a way that it washesthe sides of the bore and ushes all cuttings ol the bottom. As the uidpasses the cutting elements, they will be washed Clean. y n

'I'hus it is a general object of my invention to improve iluidcirculation by providing a drilling tool with fluid passages thatconduct the circulation fluid to a point very near the bottom of thewell to wash away all cuttings and clean the cutting elements of thetool.

It is also an object to provide a drilling tool with fluid passages suchthat the fluid washes the sides of the hole as well as the bottom.

To achieve these objects in a drilling tool having an internal -passagefor circulation uld, I provide an external channel which receives fluidfrom the internal passage and which extends down an outer face of thetool to a point near the bottom of the tool. The channel is open on oneside, and is so positioned on the tool that it is very close to thevertical wall of the well. The well wall acts as a closure for the openside of the channel and uid is, with the cooperation of the well wall,at least partially confined in the channel.

How these and other objects and advantages of the invention are attainedwill best be understood from reference to the following description andthe annexed drawing, in which:

Fig. 1 is a side elevation of a drill bit with cone cutters, the body ofthe bit being broken away to show the external water channel;

Fig. 2 is an elevation of another type oi.' bit with movable cuttersshowing the external water channel in elevation;

Fig. 3 is a fragmentary elevation partially broken away to show externalwater channels in a core head having iixed cutting blades;

Fig. 4 is a horizontal section on line 4-4 of Fig. 3; and

Fig. 5 is an elevation of a 4-way drag bit with external water channels.

There is shown in Fig. 1 a conventional type 5 of drilling bit having abody or shank I0 provided at its upper end with a threaded pin II bymeans of whichthe bit is attached to a string of drill `pipe forrotation. The cutting elements are the cone cutters I2 rotatably mountedin any suitable l0 manner upon the lower portion of body I0. Body Ill isprovided with an internal passage I5 which receives from the drill pipethe circulation fluid used to keep the cutting elements clean and carrycuttings to the surface.

The tool is provided with one or more external uid channels I8 whichcommunicate at their upper ends with internal passage I5, each channelreceiving circulation iiuid through a nozzle I9. Each channel I8 ispreferably generally U-shaped 20 in cross-section, although it will berealized that the exact shape and relative dimensions may be variedconsiderably, and lso `is open to the .tool exterior along one side aswell as at its lower end. The channel I8 is so positioned on the toolthat 25 it is in close proximity to the vertical wall 20 of the well;that is, it is placed so that the portions of the tool at the sides ofthe channel have but a small clearance between them and the sides of thewell. In this way,wal1 20 acts as a closure 30 member that at leastpartially, though usually not completely, closes the open side of the U-shaped channel I8 to confine the stream of fluid therein. Of course, theclearance between the tool and Wall 2U will permit a certain proportion35 of the circulation fluid to move outwardly, but the clearance issmall and the partial closure of the channel is suiiicient to maintainin each channel a definite downward flow of fluid confined therein andissuing for the most part at the 40 bottom of the channel.

With this construction, the stream of circulation uid issuing fromnozzle I9 -strikes wall 20' and i's deected downwardly in a stream that,45 with the cooperation of the well wall, is confined and conducteddownwardly by channel I8 to a point near the bottom of the tool where itis discharged at the bottom of the well. It will be understood that thestream of uid washes down 50 the sides of the wall before it reaches thebottom of the well where it flushes the cutters and carries awaydebris.' and that as the bit rotates in the well, each channel I8 passesin front of the entire circumference oi wall 20 so all portions bit withrolling cutters.

of wall 20 at soine time act to confine the uid stream.

Fig. 2 shows the application of the invention to another type ofdrilling tool fully described and claimed in my copending applicationSer. No. 71,600, filed March 30, 1936, on Rotary drill The bit has abody 25 upon which are rotatably mounted a pair of carriers 26, eachprovided about its periphery with a number ofcutters 21. As before,channel |8a is placed in the body of the tool where it will be in closeproximity to the walls of the well. The channel receives circulation uidat its upper end from the internal fluid passage I through nozzle 29.

Where the tool has flxed cutting elements as, for example, blades, theexternal channel may be placed in these blades instead of the body ofthe tool as described above, in order to bring it into proper positionto'cooperate with the well wall. A construction of this type is shown inFigs. 3 and 4, wherein isillustrated the lower end of a core bitcomprising a head 30 attached to the lower end of the outer barrel 3l,and an inner barrel 32 for receiving the core. Core head 30 is hereillustrated as having four cutting blades 34, although a larger orsmaller number may be used. Circulation uid flows downwardly through theannular space 36 between the inner and outer barrels and thence throughpassages 31 to the upper ends of external channels |817 which are placedone each in the outer faces of blades 34.

Since the vertical edges of blades 34 are used for reaming, the forwardedges of these blades will contact wall 20 of the hole being drilled,while the rear edge will clear'the wall slightly, as shown in Fig. 4;though after the bit has been worn, both the forward and rear edges ofthe blade may touch the hole sides, thus completely closing the openside of channel lsb. In the same manner as described before, a stream ofcirculation uidwill enter the upper end of each external channel I8bfrom passage 31 and move downwardly therein. Since it is confined withinthe channel by wall 20, which covers the open vertical side of thechannel, the stream then issues from the channel at a point near thebottom of the tool. The fluid moving downwardly through the channelwashes the walls 20 and, as the bit rotates, comes in contact with allportions of the wall.

Fig. 5 illustrates a four-blade drag bit having external water channelsI8c down the outer edges of the blades 40, in the same manner as thosedescribed in connection with Fig. 3. The extern'al channels have asection along the upper inclined portion of the blade where the wall 20is not sufficiently close to confine the stream. However, the stream offluid, after issuing from body 4i, is carried along the upper inclinedsection of channel I8c by reason of its own momentum until it strikeswall 20, by which it is deflected downwardly through the lower portionofchannel around the tool provides the path'cr channel taken by theoutgoing fluid as. it rises past the tool on its way to the groundlsurface, and that the channel for downcoming fluid is separated by partsof the tool and therefore distinct from the path taken by upwardlymoving uid.

Although I have shown the. application of my i invention to some typicaldrilling tools it will be understood that the invention may be appliedto many other tools, and may be changed without departing from thespirit and scope of my invention; and it is to be understood that theforegoing description is to be considered as illustrative of rather thanrestrictive upon the scope of the invention described in the appendedclaims.

I claim as my invention:

1. A well drilling tool with cutting elements and an internal passagefor circulation fluid, having an external iluid channel communicating atits upper end with the internal passage to receive fluid therefrom, saidexternal channel being open to the tool exterior on one vertical sideand at the lower end and so positioned on the tool in close proximity tothe vertical well wall throughout substantially its entire length thatthe well wall at least partially closes the open vertical side of thechannel to conne downwardly moving fluid therein, and a second externalchannel in which the fluid moves upwardly past the tool.

2. A well drilling tool with movable cutting elements mounted on a bodyand an internal passage for circulation fluid, having an external fluidchannel in said body communicating with the internal passage to receiveuid therefrom, said external channel being open to the tool exterior onone side and so positioned on the tool body in close proximity to thewell wall throughout substantially its entire length that the well wallat least partially closes the open side of the channel to confine fluidtherein, and a second external channel in which the fluid moves upwardlypast the tool.

3. A well drilling tool with a fixed cutting blade mounted on a body andan internal passage for circulation fluid, having an external fluidchannel in said cutting blade communicating with the internal passage toreceive fluid therefrom, said external channel being open to the toolexterior on one side and so positioned on the blade in close proximityto the well wall that the well wall at least partially closes the openside of the channel to conne fluid therein. 4. An earth boring toolcomprising cutting elements, an internal passage for circulating uid insaid tool, a channel on at least one of said cutting elements havingcommunication with said passage, said channel being open on one side atthe tool vexterior and being so positioned that when the tool is in abore the walls of the bore Willl be in close proximity to the channelthroughout substantially its entire length to close eifectively the openside of the channel and guide fluid therein.

JOI-IN A. ZUBLlN.

